1. Field of the Invention
It is common practice, particularly in analytical chemistry, to utilize evaporation of a substance, particularly a reagent such as, fox: example, a liquid solvent, to separate preselected constituents of the substance.
For said purpose, the substance is heated in a container in order to bring about accelerated evaporation. Certain conclusions may then be drawn from the residual constituents, e.g. by considering the weight or weights thereof.
Owing to the separation effect which occurs during the evaporation of evaporable fractions of a substance, it is advantageously possible through the evaporation also to separate a substance into specific constituents or also to purify a substance of specific constituents. The invention therefore also relates to the field of application of distillation.
Evaporation and/or preparation may occur under a partial vacuum or excess pressure in the container.
To accelerate the evaporation and/or preparation, the substance to be evaporated is heated, this usually entailing a pressure increase in the container.
2. Description of the Related Art
DE-OS 38 18 697 describes a heating appliance for heating and preparing sample material in at least one container under excess pressure, where, upon a pressure increase in the container as described above, the resulting gases may upon a specific pressure being exceeded escape through a pressure relief valve of the container, pass into the closed heating chamber and be extracted from there by means of an extraction device. It has also already been proposed to remove the resulting vapours or gases by means of a pipe connected directly to the container and possibly subject them to analytical evaluation.
In the case of the evaporation measures described above, the substance may be situated in a specific quantity in the container or it may by means of a substance supply line and a vapour removal line be continuously supplied and/or removed as vapour. In many cases of analytical chemistry, however, it is usual to introduce the substance into the container in a specific quantity, e.g. after weighing, and to remove the vapour or gas arising during the treatment by means of a vapour removal line.
All of the cases described above involve frequent handling of the container, e.g. for introducing the substance or removing treatment residues. However, any attempt to make handling simpler and quick is frustrated by the line connection of the container, particularly in cases where the at least one container during heating in the associated appliance is rotated or swivelled back and forth, as is the case with the above-mentioned heating appliance disclosed in DE-OS 38 18 697. In known constructions, before the container is removed or inserted in the heating appliance, the existing line connection has to be separately opened or closed, which makes handling more difficult. Furthermore, particularly in the case of a rotating holder for the at least one container, the arrangement of the line is problematical.